In the corporate world, a shit weasel is a person of similar or higher rank who'll stab you in the back, deny he did it, and blame you for the stabbing. The shit-weasel will deflect blame off of himself/herself in order to maintain his/her reputation at all cost.

That shit-weasel just blamed me for the failure of his own system and convinced the SVP it was my responsibility to begin with. Now I'm in hot water and he's getting his bonus.

a Shit Weasel is a thing encubated
in someones stomach and the person
will suffer or (accuire the power of)
really smelly farts and a bleeding anus
the farts smell of ether and bananas
i have no idea why...
also known as Byrums

oh man what the hell died in your ass?
"nothing i just have a Shit-Weasel"